From f2c1c208576fb6b4d0d4b9f3e2f8ddca0c2e7fc6 Mon Sep 17 00:00:00 2001 From: Neil Webber Date: Wed, 1 Nov 2023 09:19:36 -0500 Subject: [PATCH] updates --- NOTES | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/NOTES b/NOTES index 72f4392..f58905b 100644 --- a/NOTES +++ b/NOTES @@ -1,6 +1,31 @@ Miscellaneous notes about the emulation +****************** +ABOUT PDPASMHELPER +****************** + +This started as a way to make it easier for me to write simple +assembly-language test programs. I really wanted to avoid reimplementing +a full-blown assembler, so it was mostly about opcodes and addr modes. + +Then I got tired of hand-calculating labels for simple jumps/loops. +So the InstructionBlock was born, and the label support, including +forward references. + +The whole implementation of that is, in my opinion, a ridiculous hack and +it has a lot of rough-edges and surprising semantics. + +It is what it is; it works good enough for the pdptests and the +occasional hack/test program. The whole thing should probably just be +chucked out the window as I am not super-interested in turning +the "assembly helper" into a full-featured bug-free assembler... +It really should just be replaced with a real assembler/toolchain. + + + +**************************** RUNNING OTHER LEGACY SYSTEMS +**************************** I have tried to boot unixv6, but it requires an RK emulation. Emulating those drives should not be difficult but I just haven't gotten to it.